Water cooling problem

[fuscobal]

It seems each trackday when the outside temp goes over 20deg, my water temps go crazy from 90 to 130 and then I have to slow down for a lap in order to let things cool down. Two days ago, on Hungaroring, this happened after only 2 hard laps. Any of you guys know if it's a malfunction of the radiators (no code on vag-com) or the system simply cannot cool the water ? Is there any aftermarket solution to this, like a water radiator ?

PS : My cooling liquid was thinned with water and I've laso added some Mocool from Motul !

[the bruce]

This one:

1K0 121 212 B  additional water cooler ~ 140,-- €

+ vent, tubing, some minor parts:  200,- €– + VAT


A3 3.2 shown for example:

[fuscobal]

Well, it would be nice if it can fit somewhere behind the fog lights in order to get fresh air from the open fog grills I already have !

[the bruce]

THIS cooler is the reason why there are the open fog grills !!

 

. . . and why just the left grill is really open.

[fuscobal]

Yes but it was conceived for A3. Do we have the same room available there ? Both my grills are open, not only the left one but the left one has a plastic piece like that to direct air exactly where I see that cooler installed on your pic ! Also, supposing it has room, won't it interfere in any way with the twintercooler hose from that side ? (don't know if what I see in that pic through the grill on the low left  is also an intercooler hose)

[the bruce]

The twintercooler might be an issue. Stock GTIs have enough space of course.
The cooler has a 'Golf' part number (1K0...) and is listed in ETKA for the GTI as well.
I just have the A3 pic only, so I posted this one.

But first check if there's something wrong (VCDS temperatures). Oil should not
exceed 125° C, water about 105° C. Higher temperatures cause the ECU to
'slow down' ignition timimg.

[fuscobal]

Only happens at the track while driving very hard so can't vag-com check there because until I get back to the pits the temps go down from 120-130 to 90deg !

[fuscobal]

1) I will only use water + water wetter or equivalent (maybe the coolant was too concentrated since the colour was bright pink). I've seen race car use only water + coolant additives. The winter cooland is probably as bad for high temps as it is good for winter temps
2) Will replace the OEM radiator with a new one since I've found a small pink dot under it wich means I might have a tiny crack wich can also raise the system's temps. Was also thinking about Mishimoto but heard plenty of stories about them leaking or touching the Ac hose because of the extra thickness.

If these 2 won't work, I will have to try the optional small radiator and make it fit somewhat (I I would only know its size...). Can anyone please look into Etka (mine doesn't work anymore) and post a pic with the optional radiator connecting to the main one (need the codes for all the hoses also) ?

[tony_danza]

Odd, I've done 25-30 minutes sessions on track at a time in 25degrees+ without the temp gauge so much as moving, and that's on regular VW coolant, nothing extra.

I think you may have an issue with a sensor/thermostat/pipe/radiator/fan??

[fuscobal]

I will check everyone of them. The radiator had a small pink spot at my last check so I will replace it for sure. The fans seem to be working, don't know about the thermostat and fans though !

[tony_danza]

The MK4 Golf had a fan issue down to a faulty resister, I don't know if it affects MK5s?

Coolant temp sensor is another common one.

[fuscobal]

On 1st of march I will change the radiator, coolant temp sensor and thermostat (6 years on the existing ones, including several rack days may be enough for them). I've also ordered the VWRacing air-dam wich should help with the airflow through the radiator. Unfortunately, I can't get the VwMotorsport vented hood anywhere in Europe (mailed VwMotorsport and Carbon Becker Germany wich is the actual manufacturer but no answer...only Bildon sells them in US but very expensive + the shipping and taxes would be prohibitive if brought from there) !